EP0635640B1 - Bearing structure used in a compressor - Google Patents
Bearing structure used in a compressor Download PDFInfo
- Publication number
- EP0635640B1 EP0635640B1 EP94111226A EP94111226A EP0635640B1 EP 0635640 B1 EP0635640 B1 EP 0635640B1 EP 94111226 A EP94111226 A EP 94111226A EP 94111226 A EP94111226 A EP 94111226A EP 0635640 B1 EP0635640 B1 EP 0635640B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- cylinder
- bearing
- drive shaft
- rotary member
- compressor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/14—Control
- F04B27/16—Control of pumps with stationary cylinders
- F04B27/18—Control of pumps with stationary cylinders by varying the relative positions of a swash plate and a cylinder block
- F04B27/1804—Controlled by crankcase pressure
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B27/00—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders
- F04B27/08—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis
- F04B27/10—Multi-cylinder pumps specially adapted for elastic fluids and characterised by number or arrangement of cylinders having cylinders coaxial with, or parallel or inclined to, main shaft axis having stationary cylinders
- F04B27/1036—Component parts, details, e.g. sealings, lubrication
- F04B27/1054—Actuating elements
- F04B27/1063—Actuating-element bearing means or driving-axis bearing means
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
- F04B49/22—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves
- F04B49/225—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00 by means of valves with throttling valves or valves varying the pump inlet opening or the outlet opening
Definitions
- the present invention relates to a compressor according to the preamble of claim 1.
- an electromagnetic clutch is provided between an external driving source, such as the vehicle's engine, and the rotary shaft of the compressor. Power transmission from the driving source to the rotary shaft is controlled by the ON/OFF action of this clutch. At the time the electromagnetic clutch is activated or deactivated, the clutch's action generates a shock generally detrimental not only to the compressor but also the overall driving comfort experienced by the vehicle's passengers. In addition, the integration of the clutch with the compressor increases the overall weight of the compressor.
- This compressor comprises a first bearing disposed between a support member and a rotary member comprising a pulley and a radially extending plate mounted on the drive shaft, said plate being attractable to the pulley for transmitting a driving force from a power supply to the drive shaft.
- a bobbin 26 of the valve 24 supports a solenoid 25 on the outer periphery thereof.
- a guide cylinder 27 is fixed to the hollow portion of a bobbin 26.
- a fixed core 28 is securely retained in the guide cylinder 27.
- a movable core 29 is retained in the guide cylinder 27 in such a way that it moves to and away from the fixed core 28.
- a spring 30 is disposed between the fixed core 28 and the movable core 29. The movable core 29 is urged away from the fixed core 28 by the spring 30.
- a valve housing 31 is securely coupled to the bobbin 26 via a connecter 32.
- a spherical valve 33 is disposed in the valve housing 31.
- a first inlet port 31a, for introducing the discharge pressure therein, a second inlet port 31b for introducing the suction pressure therein and a control port 31c are formed in the valve housing 31.
- the first inlet port 31a communicates with the discharge chamber 3b via a first passage 34.
- the second inlet port 31b communicates with the suction passage 54 via a second passage 35, and the control port 31c communicates with the crank chamber 2a via a control passage 37.
- a return spring 39 and a valve seat 40 are disposed between a spring seat 38 and the valve 33 in the valve housing 31.
- the valve 33 receives the force of the return spring 39 acting in the direction to close a valve hole 31d.
- the bellows 46 With the solenoid 25 excited, the bellows 46 is displaced by an amount corresponding to the variation in suction pressure in the suction passage 54. This displacement is transmitted to the valve 33 via the rod 48.
- the opening of the valve 33 When the suction pressure is high, i.e. when cooling load is large, the opening of the valve 33 is reduced. This causes the amount of the refrigerant gas, which flows into the crank chamber 2a from the discharge chamber 3b via the passage 34, the first inlet port 31a, the valve hole 31d, the control port 31c and the control passage 37, to be reduced.
- the refrigerant gas in the crank chamber 2a flows to the suction chamber 3a via the pressure release passage 1b. This consequently reduces the pressure in the crank chamber 2a.
- the amount of the refrigerant gas flowing into the cylinder bore 1a from the suction chamber 3a gradually increases, thus resulting in a slow increase in discharge displacement.
- the discharge pressure rises slowly, so that the torque in the compressor does not change greatly in a short period of time.
- Japanese Unexamined Patent Publication No. 63-183277 discloses such a clutchless type compressor.
- the compressor according to the '277 publication discloses a radial bearing used for the second bearing member to support the rotary shaft in the compressor.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Compressors, Vaccum Pumps And Other Relevant Systems (AREA)
- Compressor (AREA)
Description
- The present invention relates to a compressor according to the preamble of
claim 1. - In general, compressor units used in automobiles, trucks and the like are used to supply compressed refrigerant gas to the vehicle's air conditioning system. To maintain air temperature inside the vehicle at a level comfortable for the vehicle's passengers, it is important to utilize a compressor whose displacement amount of the refrigerant gas is controllable. One known compressor of this type controls the inclined angle of a swash plate, tiltably supported on a rotary shaft, based on the difference between the pressure in a crank chamber and the suction pressure, and converts the rotational motion of the swash plate to the reciprocal linear motion of each piston.
- In the conventional compressor, an electromagnetic clutch is provided between an external driving source, such as the vehicle's engine, and the rotary shaft of the compressor. Power transmission from the driving source to the rotary shaft is controlled by the ON/OFF action of this clutch. At the time the electromagnetic clutch is activated or deactivated, the clutch's action generates a shock generally detrimental not only to the compressor but also the overall driving comfort experienced by the vehicle's passengers. In addition, the integration of the clutch with the compressor increases the overall weight of the compressor.
- To solve the above shortcomings, Japanese Unexamined Patent Publication No. 63-183277 discloses a variable displacement swash plate type compressor which does not employ an electromagnetic clutch for transmitting power from the external driving source to the compressor.
- In this compressor, a pair of bearing members support a rotary shaft having a pulley secured thereto for power transmission from an external driving source. One of the bearing members is provided in a cylinder block while the other bearing member is provided in the housing which defines a crank chamber. The stable support of the rotary shaft results in the reduction of the vibration and noise of the compressor. This is achieved by increasing the distance between the bearing member pair. According to the structure in which the rotary shaft is supported in the housing, however, the distance between the bearing member pair cannot be increased unless the entire length of the compressor is increased.
- According to the
document DE 40 02 196 A1 there is disclosed a compressor according to the preamble ofclaim 1. This compressor comprises a first bearing disposed between a support member and a rotary member comprising a pulley and a radially extending plate mounted on the drive shaft, said plate being attractable to the pulley for transmitting a driving force from a power supply to the drive shaft. - It is an object of the present invention to provide a compressor in which the stable support of the drive shaft is enhanced in order to suppress vibration and noise without having to enlarge the size of the compressor.
- This object is achieved by means of the combination of the features defined in
claim 1. - Preferable embodiments of the invention as set out in the subclaims.
- In the following the invention is further illustrated by embodiments with reference to the accompanying drawings in which:
- Fig. 1 is a cross-sectional side view of an entire compressor according to an embodiment of the present invention;
- Fig. 2 is a cross-sectional view along the line 2-2 in Fig. 1;
- Fig. 3 is a cross-sectional view along the line 3-3 in Fig. 1;
- Fig. 4 is a cross-sectional side view showing a swash plate at the minimum inclined angle;
- Fig. 5 is a partially enlarged cross-sectional view of the compressor, showing a blocking body at an opening position;
- Fig. 6 is a partially enlarged cross-sectional view of the compressor, showing the blocking body at a closing position and a solenoid in a de-excited state; and
- Fig. 7 is a cross-sectional side view of an entire compressor according to another embodiment.
- A compressor according to a first embodiment of the present invention for use in an air conditioning system will now be described referring to Figs. 1 through 6. The compressor as described operates without a clutch between the external driving source and the compressor.
- As shown in Fig. 1, a
front housing 2 is connected to the front end of acylinder block 1. Arear housing 3 is securely connected to the rear end of thecylinder block 1 via avalve plate 4,valve forming plates retainer forming plate 6. Thefront housing 2,cylinder block 1 andrear housing 3 constitute a casing of the compressor. Thefront housing 2 and thecylinder block 1 define acrank chamber 2a. - A
rotary shaft 9 is rotatably supported between thefront housing 2 and thecylinder block 2. The front end of therotary shaft 9 protrudes outside from thecrank chamber 2a through an opening 2b of thefront housing 2. Acylindrical holder 59 is securely fastened on this protruding end portion. Apulley 10 is fitted on theholder 59, with a key 60 intervening between thepulley 10 and theholder 59. Thekey 60 inhibits the relative rotation between thepulley 10 and theholder 59. - The
pulley 10, attached to therotary shaft 9 by a screw 61, rotates when coupled to a vehicle's running engine via abelt 11. Thepulley 10 rotates in the direction in which theholder 59 is fastened to therotary shaft 9 by the screw 61. Therefore, thepulley 10 androtary shaft 9 rotate together, in one direction. - A
support cylinder 2c protrudes from the front end of thefront housing 2 and surrounds the front end portion of therotary shaft 9. The drivenpulley 10 is rotatably supported by thesupport cylinder 2c via an angular contact ball bearing 7 which serves as a first bearing member. Thesupport cylinder 2c receives both the thrust load acting on thepulley 10 and the radial load via the angular bearing 7. - A lip seal 12, positioned between the
support cylinder 2c androtary shaft 9 proximate to the front opening 2b, prevents gas from leaking from inside the crank chamber to the outside along therotary shaft 9. - A
drive plate 8 is secured on therotary shaft 9, and aspherical slider 14 is slidably supported on therotary shaft 9. Aswash plate 15 is supported on theslider 14 in such a way as to be slidable in the axial direction of therotary shaft 9.Link pieces swash plate 15. A pair ofguide pins link pieces support arm 8a protrudes from thedrive plate 8. - A
support pin 20 is rotatably supported in thesupport arm 8a, and extends perpendicular to therotary shaft 9. The pair ofguide pins support pin 20. The interlocked action of thesupport pin 20 and theguide pins swash plate 15 not only to rock forward and backward along the axial direction of therotary shaft 9 around theslider 14, but to rotate together with therotary shaft 9. - A
cylindrical space 13 is defined in the center portion of thecylinder block 1 in the axial direction of therotary shaft 9. Amovable cylinder 21 is slidably retained in thespace 13, as shown in Figs. 1, 4 and 5. Themovable cylinder 21 has a large-diameter portion 21a and a small-diameter portion 21b. A spring 36 is interposed between astep portion 21c at the outer surface of themovable cylinder 21 and aflange portion 13a on the inner wall of thespace 13. The spring 36 urges themovable cylinder 21 toward theslider 14. - The rear end portion of the
rotary shaft 9 is fitted in the large-diameter portion 21a of themovable cylinder 21. Aball 41 is pressed against the rear end portion of therotary shaft 9 by aspring 42. Thespring 42 serves to suppress the displacement of therotary shaft 9 in the thrust direction. - A ball bearing 53 intervenes between the rear end portion of the
rotary shaft 9 and the large-diameter portion 21a of themovable cylinder 21, as shown in Fig. 5. The rear end portion of therotary shaft 9 is supported by the inner wall of thespace 13 via the ball bearing 53 and themovable cylinder 21. The ball bearing 53 has both anouter ring 53a secured to the inner surface of the large-diameter portion 21a, and aninner ring 53b which is slidable on the surface of therotary shaft 9. - As shown in Fig. 5, a
step portion 9a is formed in the outer peripheral surface of the rear end portion of therotary shaft 9, so that the movement of theinner ring 53b toward theslider 14 is restricted by thestep portion 9a. Accordingly, when the ball bearing 53 abuts on thestep portion 9a, the movement of themovable cylinder 21 toward theslider 14 is inhibited. - A
suction passage 54 is formed in the center portion of therear housing 3 as shown in Figs. 1 and 5. Thesuction passage 54 is connected to thespace 13. Apositioning surface 55 is formed around the opening of thesuction passage 54 on the side of the,space 13. When the distal end of the small-diameter portion 21b of themovable cylinder 21 moves to abut against thepositioning surface 55, the backward movement of themovable cylinder 21 is restricted and the communication between thesuction passage 54 and thespace 13 is blocked. - A
transmission cylinder 56 is slidably provided on therotary shaft 9 between theslider 14 and theball bearing 53. Thetransmission cylinder 56 has both a front end which can abut against the rear end surface of theslider 14 and a rear end that abuts against theinner ring 53b of theball bearing 53. - As the
slider 14 moves in a backward direction toward themovable cylinder 21, themovable cylinder 21 abuts thetransmission cylinder 56, pressing it against theinner ring 53b of theball bearing 53. Theball bearing 53 receives the load in the thrust direction as well as the load in the radial direction. Accordingly, themovable cylinder 21 is urged toward thepositioning surface 55 against the force of the spring 36, so that the distal end of the small-diameter portion 21b abuts on thepositioning surface 55. The swash plate's inclined angle can thus be changed to a minimum value, i.e. slightly larger than zero degrees, as shown in Fig. 4. - This occurs when the
movable cylinder 21 comes to a closing position to block the communication between thesuction passage 54 and thespace 13. Themovable cylinder 21 moves between the closing and opening positions, in response to theslider 14. It should be noted that the maximum inclined angle of theswash plate 15 is restricted by the abutment of aprojection 8b of thedrive plate 8 on theswash plate 15. - Single-
head pistons 22 are retained in cylinder bores 1a, formed through thecylinder block 1 so as to connect to the crankchamber 2a. A pair ofshoes 23 are slidably fitted over aneck 22a of thepiston 22. The peripheral portion of theswash plate 15 is inserted between theshoes 23 so that the end faces of bothshoes 23 are in contact with both surfaces of theswash plate 15. Accordingly, the rotational motion of theswash plate 15 is converted to the reciprocal motion of thepiston 22 via theshoes 23, causing thepiston 22 to reciprocate in the associatedcylinder bore 1a. - As shown in Figs. 1 and 3, a
suction chamber 3a and adischarge chamber 3b are defined in therear housing 3. Asuction port 4a and adischarge port 4b are formed on thevalve plate 4.Suction valves valve forming plates piston 22 allows the refrigerant gas in thesuction chamber 3a to push thesuction valve 5a open, and to enter each cylinder bore 1a via itscorresponding suction port 4a. - When each
piston 22 moves forward, the refrigerant gas that has entered eachcylinder bore 1a pushes eachdischarge valve 5b open and is then discharged into thedischarge chamber 3b through eachdischarge port 4b. Eachdischarge valve 5b abuts against eachretainer 6a on theretainer forming plate 6 so that the opening of thevalve 5b is restricted. - A
thrust bearing 62 intervenes between thedrive plate 8 and the front inner wall of thefront housing 2. Thethrust bearing 62 receives a reactive force due to the compressed gas which acts on thedrive plate 8 via thepistons 22,shoes 23,swash plate 15,link pieces support pin 20 in accordance with the reciprocation of thepistons 22. - The stroke of each
piston 22 changes in accordance with the difference between the pressure in thecrank chamber 2a and the suction pressure in thecylinder bore 1a. Thus, the inclined angle of theswash plate 15, which affects the compression displacement, varies. The pressure in thecrank chamber 2a is controlled by adisplacement control valve 24 that is attached to therear housing 3. Thecrank chamber 2a is connected to thesuction chamber 3a via apressure release passage 1b that serves as a restriction to the flow of gas from thesuction chamber 3a to the crankchamber 2a. - The
suction chamber 3a communicates with thespace 13 via a port 4c that is formed through eachplate movable cylinder 21 moves to the closing position, the port 4c is cut off from thesuction passage 54. It should be noted that thesuction passage 54 is an inlet port through which refrigerant gas is supplied into the compressor. Themovable cylinder 21 may cut off the communication between thesuction passage 54 and thesuction chamber 3a at the downstream portion of thesuction passage 54. - The internal structure of the
displacement control valve 24 will be described with reference to Figs. 5 and 6. - A
bobbin 26 of thevalve 24 supports asolenoid 25 on the outer periphery thereof. Aguide cylinder 27 is fixed to the hollow portion of abobbin 26. A fixedcore 28 is securely retained in theguide cylinder 27. Amovable core 29 is retained in theguide cylinder 27 in such a way that it moves to and away from the fixedcore 28. Aspring 30 is disposed between the fixedcore 28 and themovable core 29. Themovable core 29 is urged away from the fixedcore 28 by thespring 30. - A valve housing 31 is securely coupled to the
bobbin 26 via aconnecter 32. Aspherical valve 33 is disposed in the valve housing 31. Afirst inlet port 31a, for introducing the discharge pressure therein, asecond inlet port 31b for introducing the suction pressure therein and acontrol port 31c are formed in the valve housing 31. Thefirst inlet port 31a communicates with thedischarge chamber 3b via afirst passage 34. Thesecond inlet port 31b communicates with thesuction passage 54 via asecond passage 35, and thecontrol port 31c communicates with thecrank chamber 2a via acontrol passage 37. - A
return spring 39 and avalve seat 40 are disposed between aspring seat 38 and thevalve 33 in the valve housing 31. Thevalve 33 receives the force of thereturn spring 39 acting in the direction to close a valve hole 31d. - A
metal fitting 44 secured to themovable core 29 is retained in a suction-pressure sensing chamber 43, which communicates with thesecond inlet port 31b. Themetal fitting 44 is coupled to aspring seat 45 by abellows 46. Aspring 47 intervenes between themetal fitting 44 and thespring seat 45. Arod 48 is secured to thespring seat 45, with its distal end abutting on thevalve 33. Thevalve 33 opens or closes the valve hole 31d in accordance with a change in suction pressure in thechamber 43. When the valve hole 31d is closed, the communication between thefirst inlet port 31a and thecontrol port 31c is blocked. - An
outlet port 1c discharges the refrigerant gas from thedischarge chamber 3b into an externalrefrigerant circuit 49, as shown in Fig. 1. Theoutlet port 1c is connected to thesuction passage 54 by the externalrefrigerant circuit 49. Provided on the externalrefrigerant circuit 49 are acondenser 50, anexpansion valve 51 and anevaporator 52. Theexpansion valve 51 controls the amount of the refrigerant gas allowed in thecircuit 49 in accordance with a change in gas pressure on the outlet side of theevaporator 52. - A computer C controls the
solenoid 25. The computer C energizes thesolenoid 25 in accordance with the ON action of the vehicle's air-conditioner switch 57 or the OFF action of the vehicle'saccelerator switch 58. The computer c also de-energizes thesolenoid 25 in accordance with the OFF action of theswitch 57 or the ON action of theswitch 58. Fig. 1 shows a state where thesolenoid 25 is excited. With thesolenoid 25 excited, themovable core 29 is attracted to the fixedcore 28 against the force of thespring 30, as shown in Fig. 5. - With the
solenoid 25 excited, thebellows 46 is displaced by an amount corresponding to the variation in suction pressure in thesuction passage 54. This displacement is transmitted to thevalve 33 via therod 48. When the suction pressure is high, i.e. when cooling load is large, the opening of thevalve 33 is reduced. This causes the amount of the refrigerant gas, which flows into thecrank chamber 2a from thedischarge chamber 3b via thepassage 34, thefirst inlet port 31a, the valve hole 31d, thecontrol port 31c and thecontrol passage 37, to be reduced. The refrigerant gas in thecrank chamber 2a flows to thesuction chamber 3a via thepressure release passage 1b. This consequently reduces the pressure in thecrank chamber 2a. On the other hand, when the suction pressure in thecylinder bore 1a is high, the difference between the pressure in thecrank chamber 2a and the suction pressure in the cylinder bore 1a decreases. This causes the inclined angle of theswash plate 15 to increase as shown in Figs. 1 and 5. - When the suction pressure is low, i.e. when cooling load is small, on the other hand, the opening of the
valve 33 increases. This causes an increase in the amount of the refrigerant gas flowing into thecrank chamber 2a from thedischarge chamber 3b, which increases the pressure in thecrank chamber 2a. When the suction pressure in thecylinder bore 1a is low, the difference between the pressure in thecrank chamber 2a and the suction pressure in thecylinder bore 1a increases. This consequently reduces the inclined angle of the swash plate. - When the suction pressure is extremely low, i.e. when no cooling load is applied to the compressor, the opening of
valve 33 approaches the maximum. With thesolenoid 25 de-energized, in accordance with the OFF action of theswitch 57 or the ON action of theaccelerator switch 58, themovable core 29 moves away from the fixedcore 28 due to the force of thespring 30. This changes the opening of thevalve 33 to a maximum, as shown in Fig. 6. Under these circumstances, the refrigerant gas in thedischarge chamber 3b undergoes a rapid flows into thecrank chamber 2a. The consequent increase in the crank chamber's pressure quickly rises to a maximum, thus changing the inclined angle of theswash plate 15 to a minimum. - With a reduced inclined angle of the
swash plate 15, theslider 14 shifts toward themovable cylinder 21 and abuts on thetransfer cylinder 56. Thetransfer cylinder 56 pushes theinner ring 53b of theball bearing 53 backward. Thus, thetransfer cylinder 56 is held between theslider 14 and theinner ring 53b. Thetransfer cylinder 56 therefore can rotate together with therotary shaft 9. Due to the fact thetransfer cylinder 56 abuts only on theinner ring 53b of theball bearing 53, therotary shaft 9, rotates together with theslider 14, thetransfer cylinder 56 and theinner ring 53b. No sliding motion occurs between theslider 14, thetransfer cylinder 56 and theinner ring 53b. - When the
transfer cylinder 56, pressed against theball bearing 53, further moves toward themovable cylinder 21, themovable cylinder 21 is pushed toward thepositioning surface 55 so that the distal end of the small-diameter portion 21b of themovable cylinder 21 approaches thepositioning surface 55. This design effects a gradual decline in the area through which the refrigerant gas passes, i.e., from thesuction passage 54 to thesuction chamber 3a. Accordingly, the amount of the refrigerant gas supplied into the cylinder bore 1a from thesuction chamber 3a also decreases gradually, slowly reducing the discharge displacement or discharge pressure. This prevents large changes in the compressor's torque over short periods of time. - When the
movable cylinder 21 abuts on thepositioning surface 55, the flow of the refrigerant gas from the externalrefrigerant circuit 49 to thesuction chamber 3a stops. When the minimum inclined angle of the swash plate is other than at zero degrees, the gas is still discharged into thedischarge chamber 3b from thecylinder bore 1a, effected even with the minimum inclined angle of the swash plate. The gas discharged into thedischarge chamber 3b flows into thecrank chamber 2a via thefirst passage 34, thecontrol valve 24 and thecontrol passage 37. The refrigerant gas in thecrank chamber 2a flows into thesuction chamber 3a via thepressure release passage 1b, and the refrigerant gas in thesuction chamber 3a is fed into the cylinder bore 1a to be discharged into thedischarge chamber 3b. At this time, it is apparent that there are pressure differences among the pressures in thedischarge chamber 3b, thecrank chamber 2a and thesuction chamber 3a. The refrigerant gas in the compressor avoids flowing to the externalrefrigerant circuit 49, preventing frosting in theevaporator 52. - When the
switch 57 turns on or when the accelerator switch 5 turns off in the state shown in Fig. 6, thesolenoid 25 is energized. This causes themovable core 29 to be attracted to the fixedcore 28. Then, thebellows 46 contracts due to the suction pressure in thechamber 43, and thevalve 33 closes the valve hole 31d. - When there are pressure differences among the pressure in the
discharge chamber 3b, thecrank chamber 2a and thesuction chamber 3a, and when thevalve 33 closes the valve hole 31d, the pressure in thecrank chamber 2a decreases. This causes an increase to the inclined angle of the swash plate. This increase in the inclined angle causes theslider 14 to move away from themovable cylinder 21. - The
movable cylinder 21 follows the movement of theslider 14 due to the force of the spring 36, so that the distal end of the small-diameter portion 21b is separated from thepositioning surface 55. This gradually increases the area through which the refrigerant gas passes, i.e., from thesuction passage 54 to thesuction chamber 3a. As a result the amount of the refrigerant gas flowing into thesuction chamber 3a from thesuction passage 54 slowly increases. - Accordingly, the amount of the refrigerant gas flowing into the cylinder bore 1a from the
suction chamber 3a gradually increases, thus resulting in a slow increase in discharge displacement. As a result, the discharge pressure rises slowly, so that the torque in the compressor does not change greatly in a short period of time. - The
rotary shaft 9 keeps rotating unless the external driving source stops. Stable support of therotary shaft 9 is important to suppress the vibration and noise of the compressor. To ensure the stable support of therotary shaft 9, first, it is essential to increase the distance between the support positions of the pair of bearing members. According to this embodiment, theangular bearing 7, which serves the first bearing member, is arranged in front of thefront housing 2. Theball bearing 53, which serves the second bearing member, is located in thespace 13 in thecylinder block 1. This arrangement sets the distance between bothbearings - As previously described, according to the conventional structure, the first bearing member is located within the
front housing 2. The distance between the first bearing member and the second bearing member cannot be increased unless the length of thefront housing 2 is increased. - With the structure having the
angular bearing 7 on thesupport cylinder 2c according to this embodiment, however, the length of thesupport cylinder 2c is substantially the same as the length of a portion of therotary shaft 9 which protrudes from the front housing. It should be noted that this length is necessary to connect thepulley 10 to therotary shaft 9 like in the prior art. Therefore, the distance between theangular bearing 7 and theball bearing 53 becomes greater than the conventional one without increasing the length of thefront housing 2. This ensures a more stable support of therotary shaft 9 than that provided by the prior art. - The radial load from the external driving source acting onto the
pulley 10 via thebelt 11 is entirely received by thesupport cylinder 2c. The thrust load acting on thepulley 10 is also received by thesupport cylinder 2c. consequently, thepulley 10 is supported with enhanced stability. The rotary shaft secured to thepulley 10 is also supported by theangular bearing 7 with increased stability. - The smoothness in the sliding motion of the
movable cylinder 21 may inhibit a rapid torque change in the compressor. The smoothness necessitates the stable support of therotary shaft 9. In an unstable supporting state therotary shaft 9 vibrates, and the sliding motion of themovable cylinder 21 lacks smoothness. This makes it difficult to gradually change the flow of the supplied refrigerant gas. According to this embodiment, however, therotary shaft 9 has stable support allowing themovable cylinder 21 to slide with a smooth movement. - The entire radial load applied to the driven
pulley 10 via thebelt 11 from the external driving source is received by thesupport cylinder 2c. The radial load is not applied to therotary shaft 9. This produces the following advantages. - In the conventional clutchless compressor, the refrigerant gas normally distributes lubricant oil to the individual bearing members supporting the rotary shaft inside the compressor. The lip seal is usually located in front of the front bearing member in order to prevent gas in the crank chamber from leaking along the rotary shaft to the outside. Such a lip seal necessitates increasing the length of the rotary shaft protruding from the front housing. Consequently, when a load applied to the pulley, a bending moment occurs on the rotary shaft with the front bearing member serving as a fulcrum point.
- Usually the rotary shaft in the conventional compressor should be strong enough to endure the moment at least from the position where the front bearing member is located to the position where the pulley is secured. This typically necessitates increasing the diameter of the rotary shaft. Unfortunately, increasing the rotor's diameter causes an increase in the slide contact area between the lip seal and the rotary shaft. Since the lip seal is usually pressed against the rotary shaft by the pressure in the crank chamber, the increase in the slide contact area increases the sliding resistance between the rotary shaft and the lip seal. This contributes to a power loss and quickens the deterioration of the lip seal. Moreover, the increased diameter of the rotary shaft increases the peripheral velocity of the rotary shaft, further hastening the deterioration of the lip seal.
- In the present invention, however, the radial load, applied to the
pulley 10 from the external driving source, is entirely received by thesupport cylinder 2c. The diameter of therotary shaft 9 can be made smaller as compared with the conventional compressor, thus reducing the slide contact area of the lip seal 12 and therotary shaft 9. The decreased sliding area reduces sliding resistance between therotary shaft 9 and the lip seal 12, which in turn reduces the compressor's power loss and improves the durability of the lip seal 12. The reduced diameter of the rotary shaft decreases the peripheral velocity of therotary shaft 9, further improving the durability of the lip seal 12. - The present invention is not of course limited to the above described embodiment, and conical roller bearings 63 and 64 may be used as the first and second bearings Be shown, for example, in Fig. 7. The bearing 63 receives the thrust load which acts on the
pulley 10 in the direction toward thecylinder block 1 from thefront housing 2. The thrust load which acts on thepulley 10 in the direction toward thefront housing 2 from thecylinder block 1 is received by athrust bearing 62 in thefront housing 2. The conical roller bearing 64 exhibits the same function as theball bearing 53 in the above described embodiment. - Although the above described embodiments are directed to a clutchless compressor, the present invention can be applied to a clutchless compressor having no mechanism to prevent refrigerant gas from entering into the compressor from the external refrigerant circuit. Japanese Unexamined Patent Publication No. 63-183277 discloses such a clutchless type compressor. The compressor according to the '277 publication discloses a radial bearing used for the second bearing member to support the rotary shaft in the compressor.
- The present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
- A compressor includes a rotary drive shaft having a first end and a second end, both the ends being rotatably supported by opposing walls of a crank chamber defined in a casing and a swash plate tiltably mounted on the drive shaft and operably coupled with a piston in a cylinder bore. A rotation of the drive shaft results in a reciprocating movement of the piston for compressing refrigerant gas in a cylinder bore. A rotary member is secured to the first end which extends outside the casing. The rotary member supplies a power to the drive shaft from a power supply. A support member, disposed between the rotary member and the first end, protrudes outward from the casing. A first bearing, disposed between the support member and the rotary member, receives a thrust load and a radial load acting on the rotary member when the rotary member rotates. A second bearing, disposed between the casing and the second end, receives the radial load acting on the rotary member when the rotary member rotates.
Claims (9)
- A compressor including a rotary drive shaft which has a first end and a second end, both ends being rotatably supported by opposing walls of a crank chamber defined in a casing (1, 2, 3), wherein said first end extends outside the casing;
a disk tiltably mounted on a drive shaft and operably coupled with a piston for a reciprocating movement of the piston for compressing refrigerant gas in a cylinder bore,- a rotary member (10) secured to the first end of the drive shaft (9) for supplying a power to the drive shaft (9) from a power supply;- a support member (2c) securely protruding outward from the casing (1, 2, 3) and disposed between the rotary member (10) and the first end of the drive shaft (9);- a first bearing (7) disposed between the support member (2c) and the rotary member (10) for receiving a thrust load and a radial load acting on the rotary member (10) when the rotary member (10) rotates; and- a second bearing (53) disposed between the casing (1, 2, 3) and the second end for receiving the radial load acting on the rotary member (10) when the rotary member (10) rotates,characterized in that- said rotary member (10) is continually connected to the power supply; and- said first and second bearings (7, 53) support the drive shaft (9) to receive the radial load acting on the drive shaft (9). - A compressor according to claim 1, wherein the rotary member includes a pulley (10) connected to the power source via a belt.
- A compressor according to claim 1 or 2, wherein the first bearing includes an angular contact ball bearing (7).
- A compressor according to any one of claims 1 to 3, wherein the second bearing includes:a cylinder (21) slidably mounted on the second end and reciprocable along the second end of the drive shaft (9) within a predetermined range;a bearing (53) disposed between the cylinder (21) and the second end of the drive shaft (9) for receiving the radial load acting on the rotary member (10); andurging means (36) for urging the cylinder (21) and the bearing (53) toward the disk (15) to move the cylinder (21) and the bearing (53) to an extent based on an inclined angle of the disk (15).
- A compressor according to claim 4, wherein said bearing (53) is a ball bearing, wherein the second bearing further includes:a ball (41) engageable with the second end of the drive shaft (9); anda spring (42) disposed between the casing (1, 2, 3) and the second end of the drive shaft (9) for urging the ball (41) in the direction counter the thrust load.
- A compressor according to claim 4, wherein the casing includes:a cylinder block (1) having a front section and a rear section;a front housing (2) secured to the front section of the cylinder block (1);a rear housing (3) secured to the rear section of the cylinder block (1); andwherein said crank chamber (2a) is defined by the front housing (2) and the cylinder block (1).
- A compressor according to claim 6, wherein said support member (2c) is integrally formed with the front housing (2).
- A compressor according to claim 7 further comprising a center portion formed with the rear housing, said center portion having a suction chamber (3a) and a suction passage (35) for sucking the refrigerant into the suction chamber (3a); and a peripheral portion having a discharge chamber (3b), wherein the cylinder block (1) defines a space for communicating the suction chamber to the suction passage and for accommodating the cylinder (21), and wherein the cylinder (21) selectively opens and closes the suction passage (35) in accordance with the reciprocal movememt of the cylinder (21).
- A compressor according to claim 8, wherein the rear housing (3) has a valve (24) for controlling the pressure of the refrigerant in the crank chamber (2a) in response to the pressure of refrigerant in the suction passage (35).
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP05179394A JP3089901B2 (en) | 1993-07-20 | 1993-07-20 | Power transmission structure in clutchless compressor |
JP179394/93 | 1993-07-20 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0635640A1 EP0635640A1 (en) | 1995-01-25 |
EP0635640B1 true EP0635640B1 (en) | 1997-12-10 |
Family
ID=16065104
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP94111226A Expired - Lifetime EP0635640B1 (en) | 1993-07-20 | 1994-07-19 | Bearing structure used in a compressor |
Country Status (7)
Country | Link |
---|---|
US (1) | US5586870A (en) |
EP (1) | EP0635640B1 (en) |
JP (1) | JP3089901B2 (en) |
KR (1) | KR0128892B1 (en) |
CA (1) | CA2128368C (en) |
DE (1) | DE69407226T2 (en) |
TW (1) | TW270963B (en) |
Families Citing this family (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR970004811B1 (en) * | 1993-06-08 | 1997-04-04 | 가부시끼가이샤 도요다 지도쇽끼 세이샤꾸쇼 | Clutchless variable capacity single sided piston swash plate type compressor and method of controlling capacity |
KR100202786B1 (en) * | 1994-04-07 | 1999-06-15 | 이소가이 지세이 | Cooling structure of a clutchless compressor |
DE4481042T1 (en) * | 1994-07-13 | 1996-08-22 | Toyoda Automatic Loom Works | Swash plate compressor with variable displacement |
JPH08109880A (en) * | 1994-10-11 | 1996-04-30 | Toyota Autom Loom Works Ltd | Operation control system for variable displacement type compressor |
CN1083056C (en) * | 1995-04-07 | 2002-04-17 | 株式会社丰田自动织机制作所 | Lubrication method in clutchless compressor and lubrication controller |
JP3476164B2 (en) * | 1995-04-18 | 2003-12-10 | 株式会社豊田自動織機 | Power transmission structure in compressor |
IT1278540B1 (en) * | 1995-12-20 | 1997-11-24 | Faip S R L Off Mec | HIGH PRESSURE WATER PUMP |
JP3432995B2 (en) * | 1996-04-01 | 2003-08-04 | 株式会社豊田自動織機 | Control valve for variable displacement compressor |
US6010312A (en) * | 1996-07-31 | 2000-01-04 | Kabushiki Kaisha Toyoda Jidoshokki Seiksakusho | Control valve unit with independently operable valve mechanisms for variable displacement compressor |
JPH10148177A (en) * | 1996-11-20 | 1998-06-02 | Toyota Autom Loom Works Ltd | Variable displacement compressor |
JPH10281060A (en) * | 1996-12-10 | 1998-10-20 | Toyota Autom Loom Works Ltd | Variable displacement compressor |
JP3585150B2 (en) * | 1997-01-21 | 2004-11-04 | 株式会社豊田自動織機 | Control valve for variable displacement compressor |
JP3564929B2 (en) * | 1997-03-31 | 2004-09-15 | 株式会社豊田自動織機 | Compressor |
JPH10281059A (en) * | 1997-04-02 | 1998-10-20 | Sanden Corp | Pulley direct connection and variable displacement swash plate type compressor |
JP3880160B2 (en) * | 1997-10-21 | 2007-02-14 | カルソニックカンセイ株式会社 | Swash plate type variable capacity compressor |
JP2000009045A (en) * | 1998-04-21 | 2000-01-11 | Toyota Autom Loom Works Ltd | Control valve for variable displacement type compressor, variable displacement type compressor, and variable setting method for set suction pressure |
JP2000205127A (en) * | 1998-11-11 | 2000-07-25 | Sanden Corp | Compressor |
JP2000283028A (en) | 1999-03-26 | 2000-10-10 | Toyota Autom Loom Works Ltd | Variable displacement type compressor |
US6402480B1 (en) | 2000-12-22 | 2002-06-11 | Visteon Global Technologies, Inc. | Lubrication passage for swash plate type compressor |
JP5008754B2 (en) * | 2010-07-14 | 2012-08-22 | シーケーディ株式会社 | Tube fluorescent lamp molding equipment |
KR20220031732A (en) | 2011-03-04 | 2022-03-11 | 뉴젠 세러퓨틱스 인코포레이티드 | Alkyne substituted quinazoline compound and methods of use |
CN103557139B (en) * | 2013-10-15 | 2016-05-04 | 浙江鸿友压缩机制造有限公司 | A kind of oilless (oil free) compressor with tolerance formula limit rotation mechanism |
US10605238B2 (en) | 2017-10-23 | 2020-03-31 | Henry C. Chu | Control valve for compressor |
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Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2503273B1 (en) * | 1981-04-02 | 1986-02-21 | Messier Hispano Sa | HYDRAULIC PUMP |
US4475871A (en) * | 1982-08-02 | 1984-10-09 | Borg-Warner Corporation | Variable displacement compressor |
JPH0819904B2 (en) * | 1987-01-27 | 1996-03-04 | カルソニック株式会社 | Variable capacity swash plate type compressor |
JPS63243469A (en) * | 1987-03-28 | 1988-10-11 | Toyota Autom Loom Works Ltd | Pressure control mechanism of crank case for swash plate type compressor |
US5059097A (en) * | 1989-01-26 | 1991-10-22 | Diesel Kiki Co. Ltd. | Variable capacity wobble plate compressor |
JP2967369B2 (en) * | 1990-12-28 | 1999-10-25 | 本田技研工業株式会社 | Water pump |
JPH04318291A (en) * | 1991-04-15 | 1992-11-09 | Sanden Corp | Variable displacement swash plate type compressor |
JPH05263755A (en) * | 1992-03-23 | 1993-10-12 | Toyota Autom Loom Works Ltd | Fluid machine |
-
1993
- 1993-07-20 JP JP05179394A patent/JP3089901B2/en not_active Expired - Fee Related
-
1994
- 1994-06-22 TW TW083105682A patent/TW270963B/zh active
- 1994-07-14 KR KR1019940017198A patent/KR0128892B1/en not_active IP Right Cessation
- 1994-07-19 CA CA002128368A patent/CA2128368C/en not_active Expired - Fee Related
- 1994-07-19 DE DE69407226T patent/DE69407226T2/en not_active Expired - Fee Related
- 1994-07-19 EP EP94111226A patent/EP0635640B1/en not_active Expired - Lifetime
- 1994-07-19 US US08/277,347 patent/US5586870A/en not_active Expired - Fee Related
Also Published As
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CA2128368C (en) | 1999-04-06 |
JP3089901B2 (en) | 2000-09-18 |
KR0128892B1 (en) | 1998-04-09 |
DE69407226T2 (en) | 1998-04-23 |
KR950003651A (en) | 1995-02-17 |
US5586870A (en) | 1996-12-24 |
DE69407226D1 (en) | 1998-01-22 |
EP0635640A1 (en) | 1995-01-25 |
JPH0735040A (en) | 1995-02-03 |
CA2128368A1 (en) | 1995-01-21 |
TW270963B (en) | 1996-02-21 |
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